I've read a few places that the AFM has an intake air temp sensor built into it, yet theres also one (on both turbo and NA) before the throttle body. Why are there two seperate ones? it makes more sense for the turbo, as the air would be a bit hotter after the turbo & IC, but on the NA? Are they used for different processes by the ECU?

 

the density of air varies with temprature, so the amount of air flowing thru the afm at a given angle, is temp dependent, so they have door angle + temp to give = load. so the ecu kinda looks at these as one number



the other sensor doesnt do much in an na, more in a turbo.